Geomorphological Evolution of Palaeosurfaces in the Central Eastern Desert of Egypt

Badawy, Moawad; Bakry, Ibrahem Sayed Saber

doi:10.21608/bsge.2023.327833

Geomorphological Evolution of Palaeosurfaces in the Central Eastern Desert of Egypt

Document Type : Original Article

Authors

¹ Dept. of Geography and GIS, Faculty of Arts, Ain Shams University

² Department of Geography & GIS, College of Arts, King Faisal University- Kingdom of Saudi Arabia, Department of Geography, Faculty of Women, Ain Shams University, Cairo, Egypt.

10.21608/bsge.2023.327833

Abstract

The Red Sea Mountains are extremely rugged and have been inferred as a vast old erosion surface underwent multiple uplifting. The present study aims to recognize the old paleosurfaces in the Central Eastern Desert of Egypt to reveal their implications to the geomorphologic evolution. The study based mainly on field study, geological and topographic maps integrated with remotely sensed data and DEM.
The study distinguished between two palaeosurfaces, they are: exhumed and buried palaeosurfaces. The exhumed one is more or less flat distinguished with low relief. The buried erosion surfaces were discovered on the eastern low cliff of Jabal Naqarrah and they have a vast extent in Jabal Abu Shaara west of Hurghada. These surfaces are preserved in very constricted rock outcrops. Two phases of denudation were proposed: 1.Hammamat Phase that took place ~680-640 Ma, where significant volumes of igneous rocks were vigorously eroded; 2. the later phase took place ~33.9-11.6 Ma where a great hiatus in the sedimentation cycle has been observed between the Pre-rift sediments and the coastal Syn-rift sediments. According to the study these palaeosurfaces are polygenetic denudation surfaces. The study supposed two episodes of landscape evolution. The first episode began with the elevation of the Arabo-Nubian Shield accompanied with the early rise of Dokhan Volcanics ~ 620/600-590 Ma. The second episode started where more or less of the area was covered by the pre-rift sediments (probably Cretaceous). During early Oligocene-Middle Miocene the surface mostly formed etchplain and rate of erosion was estimated as 1mm/44.6 yr.

Keywords